Windows Phone: Moving Sprites

_Welcome back to the Windows Phone 7 Development tutorial!Today
we are going to move the sprite we created in tutorial 2 by changing
the spritePosition vector. I also resized the sprite to 64x64 to make it
a bit bigger. :)

What we
will do is to change the spritePosition.X variable so our character
moves from one side of the screen to the other. Once it reaches the
left/right side of the screen, it will change the direction and move to
the other side of the screen.

_This tutorial will only focus on the Update function of our game, and a new function we will create named MoveCharacter.All
the code that will move our character will happen inside the
MoveCharacter function. In order to make this run based on time( so our
character won't move faster on a device/computer that is faster than
another device/computer), we will pass the gameTime timer from Update to
the MoveCharacter function.We start by adding the global variable spriteDirection
to our global variables as an integer value of 1, and then creating the
MoveCharacter function, add this function to our game class:int spriteDirection = 1;protected void MoveCharacter(GameTime gameTime){ spritePosition.X += (float)gameTime.ElapsedGameTime.Milliseconds / 10.0f * spriteDirection;if (spritePosition.X >= 400.0f) spriteDirection *= -1;if (spritePosition.X <= 50.0f) spriteDirection *= -1;} This
functions takes the gameTime variable, and adds the elapsed game time
in milliseconds * spriteDirection to the X direction of our
spritePosition. spriteDirection used to change the direction the
character moves. If the characters is on the right side, we multiply the
direction with -1, making the value spritePosition.X is added with,
negative. This will make it move to the left side of the screen instead.
If the character is on the left side of the screen, we multiply the
negative value by -1 again, making it positive.This will make the character move back and forth between X=50 and X=400.Next, we will have to call the MoveCharacter(..) function we just created from the games Update() loop.MoveCharacter(gameTime);The code should look something like this:

_Now, hit F5 to build, compile and deploy your game to the emulator and see it all in action!

_And that ends this tutorial. It was very simple, but it sure creates some movements to our game!